I'm in the market for a powerful but lightweight amp. I've been comparing the Carvin BR515N with the GK MB212. The Carvin has many more features, is made in the US, and the head is removable - but it weighs 52 lbs. The GK is made in China, has a simpler preamp (not necessarily a bad thing), and it can only be used as a combo amp - but it weighs 39 lbs. I think I'd prefer the Carvin, but my concern is that they've had a lot of BX500 heads in these combos fail. How's the reliability on the MB212? I know it's new but are you folks hearing of them fail?